Screening machine and vibrating hammer therefor



H. K. NAJARIAN. SCREENING MACHINE AND VIBRATING HAMMER THEREFOR.

APPLICATION FILED JUNE 18, 1921.

1942 5p39n Patented Aug. 8, 1922.

4 SHEETSSHEET 1.

H. K. NAJARIAN.

SCREENING MACHINE AND VIBRATING HAMMER THEREFOR.

APPLICATION FILED JUNE 18, I921.

Patenteol Aug. 8, 1922.

{SHEETS-SHEET 2.

H. K. NAIARIAN.

SCREENING MACHINE AND VIBRATING HAMMER THEREFOR.

APPLICATION FILED IUNE 18,-1921- Patented Aug. 8, 1922.

4 SHEETS-SHEET 3.

LQZSQSQO m kl ATTORNEY H. K. NAJARIAN.

SCREENING MACHINE AND VIBRATING HAMMER THEREFOR.

APPLICATION FILED JUNE 18, 1921.

3L 425;089, Patented; Aug. 922.

EETSS EE 4- PATENT @FFHCE.

HERAND K. NAJARIAN, 01E SALT LAKE CITY, UTAH.

SCREENING- MACHINE AND VIBBATING- HAHN/SEER THERIEFQR.

iaiaaoae.

Specification of Letters Patent.

Patented Ring. 8, 11922.

Application filed June 18, 1921. Serial No. 478,792.

To all whom it may concern:

Be it known that I, HERAND K. NAJARIAN, a citizen of the United States, residing at Salt Lake City, county of Salt Lake and State of Utah, have invented certain new and useful Improvements in Screening Machines and Vibrating Hammers Therefor; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to'which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

My invention relates to a screening or sifting machine in which a vibrating hammer suspended by yielding arms and rapidly vibrating, while in operation, in the path of a distorted ellipse, delivers alternate and preferably vertically disposed blows in substantially diametrically opposite directions, to an inclinely placed rigid frame supported yieldingly on external supports, and carrying a screen cloth thereon, and out of contact with said vibrating hammer while inoperative. Said blows vibrate said screen frame and cloth at a uniform rate of concentration throughout the extent of said screen, and in a lineal. path, twice during each complete cycle of vibration of said vibrating hammer, once in one-direction and once in a diametrically opposite direction, preferably upward and downward, from the initial position of rest of said screen frame. Said upward blow and upward'vibration of the screen produces movement in the bed of material passing over the screen, resulting in segregating the finer particles in the bed towards the undersurface and segregating the coarser particles toward the outer surface of said bed of maproduce a screening machine of high eifi ciency, large capacity and of comparatively low cost; second, to produce a movement in the screen cloth which will dislodge particles of material blocking the apertures therein,

and also keep the said apertures continually open, thus reducing cost of attendance to a minimum; third, to reduce repairs and renewals of parts of machine to a minimum by employing standardized equipment as parts of the machine and a minimum number of parts susceptible to rapid wear and breakage.

My screening machine is suitable for sifting or screening of comminuted material, such as crushed ore or rock, sand, gravel, cement, coal, coke, flour or analogous substances and materials.

Referring to the accompanying drawings for a more complete explanation of my screening machine and vibrating hammer therefor:

Fig. l is a plan View of my screening machine.

Fig. 2 is a vertical cross section of part of inclined screen cloth and bed of material over it, showing manner in which wedge shaped particles and aggregations thereof clog the apertures in the screen cloth.

Fig. 3, is a vertical cross section, taken on line 33 of Fig. 1 and looking in the direction of the arrows.

Fig. 4 is a partial longitudinal section of screen cloth, frame and supporting arms taken on line t-4 of Fig. 3 and looking in the direction of the arrows.

Fig. 5 is a longitudinal vertical section of vibrating hammer, taken on line 5-5 of Figs. 6 and 8 and looking in the direction of the arrows.

Fig. 6, is an end view of the vibrating hammer looking in the direction of arrows 66 in Fig. 5. I

Fig. 7 is a diagram illustrating the approximate path of vibration of a point of the vibrating hammer.

Fig. 8 is a vertical cross section of the vibrating hammer taken on line 8-8 of Fig. 5 and looking in the direction of the arrows.

Fig. 9 is an end view of the nose of the vibrating hammer, illustrating toggles of circular cross section.

Fig. 10 is a cross section of the same taken on line 10-10 of Fig. 9 and looking in the direction of the arrows.

I will first describe the construction and operation of my vibrating hammer. Referring to Figs. 5, 6 and 8, 1 is a bell shaped casing, made of suitable material such as cast iron or steel and consisting of a hollow cylindrical wall of circular cross section on the inside periphery and having a reof said casing and centrall movable endwall 15 at one end, closed at the opposite end, and having a cylindrlcal projection 2 extending inwardly from the :inside surface of the closed end of said casing and preferably concentric with said casing, and a vibrator nose 3 protruding from the outside surface of the closed end located with respect to axis thereof. 11 the outside cylindrical surface of said vibrator casing,

are hollow wings 4 which serve as recepta- -cles for yielding arms 5 (Figs. 1 and 3).

On the centrally located inside projection 2 of-the vibrator casing and rigidly mounted thereon, is a ball or roller bearing .6.-

My drawing shows a roller bearing consisting .ofinner casing 7, rollers 8 and outer casing 9. .10 is a hollow circular cylinder rotatably mounted on bearing 6 and having a wall of uniform thickness except, as indicated, between point X-X, where said wall is considerably thicker, thus producing v an unbalanced weight rotatable on bearing 6 around the common axis of projection. 2 and vibrator casing 1.

Rotative motion is imparted to the weighted cylinder 10 by means of pins 11 loosely held in holes on the inwardly pro- 'jecting'flange thereof and securely held on the spider 12, said spider being securely mounted'on shaft 13 which in turn is rotatably held in bearings 1 f one of said bean ings being carried by the inside pro'ection 2 of the vibrator casing and the ot er in the removable end wall 15. Shaft 13 may be rotated by any suitable means, as for instance, by pulley 16 mounted on projecting end of said shaft as shown. The object in rotating the weighted cylinder 10' by means of pins loosely held in its inward flange is to prevent the heavy load due to centrifugal force created in said weighted cylinder and coming on bearing 6, from being transmittedto the driving shaft 13 which is necessarily-small in diameter. Excessive weight on this shaft would soon destroy the bearings 14 carrying same.

When the weighted cylinder 10 is rapidly rotated, as hereinbefore described, an unbalanced centrifugal force is created within 1 said weighted; cylinder, due to the unbalanced weight of the thicker portion X X, the intensity of said force depending on the unbalanced weight and the speed of rotation.

Referring now to Figs. 1 and. 3, 5 indicates yielding arms on which the vibrating hammer 17 is supported, preferably centrally, said arms being firmly held in wings t of vibrator casing 1 (Fig. 8). The ex: tremities of yielding arms 5 are firmly held in bearings 18 which in turn arerigidly fastened to and-carried on external supports 19. The yielding arms are constructed of some suitable resilient material, such as aeaaoee steel or lon fibred wood, and are preferably made circu ar in cross section so as to make them equally flexible in all directions. My drawings show'yielding arms made of wood.

The unbalanced force created by rapid rotation of weighted cylinder 10 is transmitted to the vibrator casing through the bearing 6 and the inside projection 2 causing it to vibrate in the path of a distorted ellipse, the supporting arms yielding at all times in the direction of the force exerted upon them by the combination of the unbalanced centrifugal force and the force of gravity acting on the mass of said vibrator casing as a unit.

Referring to Fig. 7 assuming that center point C represents the location of any point on the vibrating hammer while the same is at rest, the path of said point when the vibrating hammer is in operation may be represented by broken line 20. The magnitude-and direction of vibration at different stages of a complete cycle of vibration, neglecting the 'pull of belt on pulley 16 and.

effect of hammer blows, may be representeddiagrammatically by arrows R, R", R' and R Thus, when the unbalanced centrifugal force .is acting vertically upwards, the resultant force producing the vibration will equal the centrifugal force minus the" force of gravity acting 'on the mass of vibrating hammer, while, when the centrifugal force is acting vertically downwards, the total vibrating force will be the sum-of said centrifugal force and the force of gravity acting on the mass of vibrating hammer, and at all intermediatepoints the vibrating force will be the resultant'of all forces acting on said vibrator casing.

In Figs. ,6, 9 and 10 are shown the means employed in transmitting the elliptical vibrations of the "vibrating hammer, 17, to

the receiving ring 21, said receiving ring being out of contact from said vibrating hammer while thelatter is inoperative, but during operation, receiving the blows and vibrations of said vibrating hammer, the receiving ring itself vibrating onl in a lineal path in hontrast to the elliptical vibration of the vibrating hammer. The distance between the engaging. surfaces of theing ring in the form of lineal vibrations is accomplished by means of variously designed devices which I term toggles. Fig. 6 shows one form of transmission'toggle and receiving ring adapted to produce jarring and hammer action on the screen, this jarring and hammering effect on the screen being more suitable for efficient screening and sifting of very fine and moist material, such as clay, wet ore, etc. The transmission toggles and the receiving ring shown on Figs. 9 and 10 produce more amplitude of vibration rather than jarring and hammering action, this form of vibration in the screen being more suitable for screenin coarse and dry material such as coarse san gravel, etc.

In Fig. 6, 3 indicates the vibrator nose in end elevation. Toggles 27 are held, at one end, loosely in grooves 28 cut in the vibrator nose, both the grooves and the end of the toggles which are free to rotate partially therein being circular in cross section. The other end of the toggles are free to slide in grooves 29 in the receiving ring 21. 22 indicates the upper end of the transmitter plate which is secured to receiving ring 21 by means of rivets 30. When the vibrating hammer 17 is in operation, the vibrator nose 3 being an integral part thereof vibrates with it in its elliptical path. The ends of the toggles held in grooves 28 likewise vibrate with the vibrator nose in its elliptical path, the free ends of toggles, however, can only slide in a substantially lineal path, up and down, in the grooves 29 ofthe receiving ring, thus impinging against the bottom of groove 29 'in its upward and downward strokes and delivering an initial blow to the receiving ring with each stroke and subseuently vibrating said receiving ring in a lineal path substantially downwards and upwards.

In Figs. 9 and 10,1 is a portion of the vibrator casing shown in section, 3 is the vibrator nose shown in section and end elevation, and 21 is the receiving ring shown in end elevation in Fig. 9 and in section in' Fig. 10. Toggles 31 of circular cross section are loosely and rotatably heldin corresponding grooves of circular cross section cut in the vibrator nose 3 and designed to deliver blows and vibration in a substantially up and down direction, although they maybe designed to transmit said blows and vibrations in any desired angle or direction. A washer 32. is fastened tothe end of the vibrator nose 3 by means of cap screw 33 to hold toggles 31 in place. It is evident that toggles 31 can transmit blows and vibrations to the receiving ring 21 only in lines perpendicular to inside faces 34 and 35 of said receiving ring. Thus at any time during the cycle of elliptical vibration of the vibrator nose, no matter in which direction said vibrating force in the vibrator nose is acting, the forces that can be transmitted to the receiving ring surfaces 34 and 35 will be the vertically upward and downward component of said vibrating forces. The component of forces in the vibrator nose tending to move the vibrator ,nose in other than, up and down directions serves. only to roll said circular toggles against the inside faces of the receiving ringbeing rigidly fastened to hollow pipes 23..

Passing through said hollow pipes 23 and rigidly fastened thereto by means of bolts 37 are flexible arms 38 preferably of wood, the

ends of which project beyond the end of said hollow pipes and are securely held in bearings 39 which in turn are secured to and carried by external supports, 19. The'screen frame thus mounted on said flexible arm is free to vibrate in any direction.

The lower end of transmitter plate 22 is also securely fastened to the hollow pipes 23, preferably at the center, the upper end of the transmitter plate being securely fastened to the receiving ring (Figs. 3, 5 and 6). Thus the receiving ring is held in its normal position and out of contact with the vibrating hammer by means of the transmitter plate extending upwardly from the hollow pipes 23.

The hollow pipes 23 are rigid throughout their whole length and the lineal vibrations transmitted to them from the transmitter plate 22 vibrates said hollow pipes at a uniform rate over their whole length. Likewise, the vibrations transmitted to the frame supports 24: are equal in intensity throughout, thus producing uniform lineal vibrations in the screen frame 25 and the screen mounted thereon, producing vibrations of uniform concentration throughout the extent of said screen.

The screen cloth is shown mounted on the frame in the form of arches. This is to prevent deflection in the screen cloth and remer :and the downward vibration suddenly jerks and removes the wires 40 from under the bed of material in the direction of arrows a -a etc. thus dislodging particles of material wedged in the apertures between said wires either singly 41 or in aggrega- 'tions 42. The particles thus dislodged will be caughtin the stream of material traveling downwardly over the incline screen in the direction of arrow A and carried forward, thus freeing the apertures of clogging particles.

The upward blow and vibration'will be transmitted to the bed of material in the direction of the arrows 5-?) .etc. This motion will throw the particles of material away fromthe surface of the screen. As

the smaller particles in the bed of material thus thrown in the air have shorter trajectories than the larger particles, the said upward blow and vibration will result insegregating the finer particles toward the undersurface of the bed of material, the

coarser particles likewise segregating toward the outer surface of said bed of material and away from the screen cloth. This will result in the finer particles passing throughthe'apertures in the screen without necting said hammer to said support, said hammer comprising means for causing it to vibrate in the path of a distorted ellipse,

means for transmitting vibrations from said hammer to said fram and rigidly connected to the latter, means cooperating with said motor for receiving vibrations therefrom, said means being out of contact with said hammer when the latter is inoperative but adapted to receive alternately directed blows from said hammer when the latter operates, and transmit the same to the screen frame thereby causing said frame and screen to vibrate in a lineal ath twice during each cycle of elliptical vi ration of the hammer once in a downwardly and once in an upwardly direction, from the initial position of rest of said screen frame.

2. In a screeningmachin comprlsing a support, a frame carrying a screen, means for yieldingly connecting said screen to said support and means for transmitting vibrations to said frame and screen from a vibrating hammer yieldingly secured to said support, said vibrating hammer comprising a casing having one end closed, an inwardly projecting cylindrical portion' forming a part of said end closure, removable means for closing the other end ofsaid casing, an unbalanced cylindrical ring rotatably mounted on said cylindrical portion,'means for rotating said ring comprising a shaft journaled in said removable end closure and said cylindrical rojection, a flange rigidly secured to said s aft intermediate the bearings thereof, loose coupling means joining sa1d flan e to said ring, whereby the turning of said s aft will rotate the unbalanced ring and cause the hammer casing to vibrate, .in the path of a distorted ellipse, a protruding portion on the end of said hammer casing, and means carried thereby for cooperating with the motion transmitting means.

3. A method of screening materials comprising passing a bed of material over a yieldingly supported inclined screen, subjecting said screen to successive hammer blows in alternately opposite directions and to lineal vibrations of uniform intensity throughout its entire extent, one of said blows causing the particles of material clogging. the apertures of said screen to be dislodged therefrom and the oppositel directed blows causing a segregation 0 said finer particles of said material to the undersurface of said bed and the coarser material to the top of said bed.

4. A method of screening materials .comprising passing a bed of material over a yieldingly supported inclined screen, subjecting said screen to successive hammer blows in alternately upwardly. and downwardly directions and to lineal vibrations of uniform intensity throughout its entire extent, the downwardly directed blows causing the particles of material clogging the apertures of said screen to be dislodged therefrom and the upwardly directed blows causing a segregation of saidfiner particles of sa1d material to the undersurface and the gogrser material to the top surface of said 5. In a screening machine comprising a support, a vibratingh'ammer yieldingly connected therewith, a screen frame yieldingly connected to said support and means for transmitting the vertical components of said vibrations to said screen, a screen frame comprising rigid hollow pipes, frame supports rigidly fastened thereon, a'rigi'd screen frame carried by said supports, screen cloth mounted on said frame, flexible supporting arms passing through said hollow pipes and means securing said supporting arms to said hollow pipes.

6. In a screening machine comprising a support, a vibrating hammer yieldingly connaaaoee nectedtherewith and a screen frame yieldingly connected to said support by means comprising hollow pipes rigidly fastened to said screen frame, flexible supporting arms passing through said pipes, means securing said flexible arms to said pipes and means securing the-ends of said flexible supporting arms to said support. 1

In a screening machine, comprising a support, a vibrating hammer yieldingly connected to said support, a screen frame yield-i v ingly connected to said supportand motion transmitting means between said hammer and, said screen frame, said motlon transmitting means comprising a pro ecting portion on said hammer, toggles carried thereby and vibrating therewith, a plate rigidly sea ring carried one end of said plate and enclosing the cured to the screen frame, y

projecting portion and the toggles carried a projecting portion carried by said hammer and provided with toggles one end of which is secured to said projection and vibrates with it, a ring carried by said plate and enclosing said projection and toggles, grooves in said ring for the reception of said toggles and in which the toggles are free to slide fora portion of their movement whereby a hammer blow is imparted to said ring andtransmitted to the screen.

9. In a screening machine. having a sup-.

port, and a screen frame yieldingly connected therewith, means. for vibrating said screen through the medium of hammer blows, "said means comprising means for producing non-linear vibrations through the rotation of an unbalanced ring, means for converting said non-linear vibrations into linear vibrations, comprising a member having a lost motion connection with the rotating ring. v -v 10. In a screening machine, a support and a screen frame yieldingly connected therewith, a body vibrating in a closed non-linear path, means for transmitting to the screen the components of said vibrations normal to the surface thereof, said means comprising a member having a lost motion connec-' tion with said vibrating body whereby the vibrations transmitted will be in the form of hammer blows.

in testimon whereof I afix my signature,

BRAND K. NAJARIAN. 

